Right swollen foot that won't go down causing severe pain up leg up to the knee, for about six months now after cellitius skin infection, not pitting?

Non pitting edema. Many things can cause swelling of the extremities; trauma, infections, problems with veins, problems with the lymphatics system, heart issues, kidney disease to name a few. I would recommend evaluation by your physician. Elevation and compression stockings may be helpful to treat the swollen areas.